I’m not sure I would call it a bubble, it folds over the ends on its self making it resistant to splitting at the ends. You will always find a “double flare” on brake and high pressure fuel lines. The tool looks the same except it comes with small “inserts” for each size tube. When you compress the end of the tube, the insert rolls over the ends, and then you press it again to “set” the double flare. The fitting are the same. Only the tubing wont split from vibrations, compression, or what ever. As far as the seamless tubing, that is available at any good FLAPS.  You’ll be glad you spent the extra bucks, with piece of mind!

Skipper

From: Jim Felder 
Sent: Friday, April 03, 2015 11:53 AM
To: Walking Boss 
Cc: Vanagon mailing list 
Subject: Re: Propane lines

Is that the kind that makes the bubble? I an not sure it is compatible with fitting on the westy, but I'm no expert. I have had no trouble out of the flares. I did not even run across seamed tubing when I was looking, maybe the manufacturers have gotten wise to that. 

Jim

On Fri, Apr 3, 2015 at 11:51 AM, Walking Boss <walkingboss@communicomm.com> wrote:

  A little advice,....... 1) get a double flaring tool,  2) use seamless
  tubing. Much better to be safe that save a few bucks!

  Skipper 

  -----Original Message-----
  From: Stuart MacMillan
  Sent: Friday, April 03, 2015 11:43 AM
  To: vanagon@GERRY.VANAGON.COM
  Subject: Re: [VANAGON] Propane lines

  It's best to run a complete new copper tube. Get a flaring tool here:
  http://www.harborfreight.com/7-piece-tube-flaring-kit-5969.html.

  Stuart

  -----Original Message-----
  From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
  Michael
  Sent: Friday, April 03, 2015 9:25 AM
  To: vanagon@GERRY.VANAGON.COM
  Subject: Propane lines

  Hello vanagon community,

  Awhile back I took off the old rusted propane tank and in the process of
  doing so, broke the top copper propane line. So right now it's a twisted
  mess on the tank end.

  Also, the nut came off as well. I have zero experience with flaring and my
  question is this: what is the best way to cut that pipe and get the nut back
  on so it can be connected to the new Gowesty regulator?